Adiabatic and nonadiabatic perturbations for loop quantum cosmology

作者：Li, Yu; Zhu, Jian-Yang^*

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2012, 85(2): 023515.

DOI：10.1103/PhysRevD.85.023515

We generalize the perturbations theory of loop quantum cosmology to a hydrodynamical form and define an effective curvature perturbation on a uniform-density hypersurfaces zeta(e). As in the classical cosmology, zeta(e) should be gauge-invariant and conservative on the large scale. The evolutions of both the adiabatic and the nonadiabatic perturbations for a multifluid model are investigated in the framework of the effective hydrodynamical theory of loop quantum cosmology with the inverse-triad correction. We find that, different from the classical cosmology, the evolution of the large-scale nonadiabatic entropy perturbation can be driven by an adiabatic curvature perturbation and this adiabatic source for the nonadiabatic perturbation is a quantum effect. As an application of the related formalism, we study a decay model and give out the numerical results.

• 出版日期2012-1-12
• 单位北京师范大学